Blowout panels



July 25, 1967 R. HAwEs ETAL 3,332,175

BLOWOUT PANELS Filed Jan. 29, 1,965

INVENTORS /QQoEe ici/@V55 L ONA D cHAz/f fl gi@ BY ,055,27 SL55 APATENT AGEN United States Patent 3,332,175 BLOWOUT PANELS Robert Irvin Hawes, Weymouth, Dorset, England, and Ronald C. Sehaubel, Toronto, Ontario, and Robert Isles, Erindale, Ontario, Canada, assignors to Atomic Energy of Canada Limited, Ottawa, Ontario, Canada Filed Jan. 29, 1965, Ser. No. 429,092 Claims priority, application Canada, Sept. 28, 1964,

ABSTRACT OF THE DISCLOSURE A pressure retaining wall consists of a number of blowout panels supported to cover apertures in `a framework. Each pair of blowout panels is restrained from outward movement in one direction by having one edge abutting against a vacuum panel. The vacuum panel is, in turn, held against a portion of the framework by suction. When the pressure differential between the two sides of the wall exceeds a predetermined amount the vacuum panel is forced away from its operative position breaking the suction and permitting the blowout panels to be swept away from the framework through the apertures. Where several pairs of blowout panels are used the suction supporting the associated vacuum panels is supplied from the common source 'so that the removal of one vacuum panel causes the suction supporting the remaining vacuum panels to be broken and causes all the blowout panels to be swept away simultaneously.

This invention relates to a structure for effecting a rapid pressure reduction in an enclosure when the pressure in the enclosure exceeds a predetermined value. In particular, it relates to a wall structure for sealing olf 4an enclosure, which is capable of rapid collapse when the pressure on one side exceeds the pressure on the other side by a predetermined amount.

It is, of course, well known to use safety valves and similar devices for restricting the pressure within an enclosure to a predetermined value. Such devices, however, cannot give rapid relief to a sudden rise in pressure, due to limitations in x-sectional area.

It is therefore an object of this invention to provide a wall structure which will collapse when the pressure on one side exceeds the pressure on the other side by a predetermined amount.

It is a further object -of this invention to provide a wall composed of basic modules so arranged that when unbalanced pressures on its two sides cause one module to collapse the remaining modules are also caused to collapse.

Briefly, this invention comprises a wall framework which supports an arrangement of large panels, known as blowout panels. The blowout panels are arranged in pairs and each pair is normally held in position by a panel of smaller are-a, known as a vacuum panel or locking member. The v-acuum panel is in its turn supported by suction supplied by holding means against part of the wall framework. When the pressure in any enclosure contained by the wall exceeds the pressure outside the wall -by a predetermined amount the vacuum panel is displaced from its normal position breaking the suction effect which ysupports it. The forces provided by the unbalanced pressures cause the blowout panels and vacuum panel to be swept `away from the wall framework allowing a rapid reduction of the pressure within the enclosure. In a wall formed by several pairs of blowout panels the removal of one vacuum panel `causes the suction supporting the remaining vacuum panels to be broken and hence per- Vmits the removal of all the panels in the wall.

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The features and objects of the invention will become apparent from the following description of a specific embodiment of the invention taken in conjunction with the accompanying drawings in which:

FIGURE 1 is an elevational view of a wall module with the vacuum panel omitted, and

FIGURE 2 is a cross-sectional view ofthe wall module, taken along the line 2-2 of FIGURE 1, with the vacuum panel in position, and

FIGURE 3 is Ian elevational view of a wall structure composed of two modules of the type shown in FIG- URE 1. v

A specific embodiment of the invention to be described is adapted for use in a nuclear reactor building in which a fuelling machine enclosure is normally operated with an atmosphere of carbon dioxide kept at a pressure slightly in excess of atmospheric. The remainder of the building contains air at normal atmospheric pressure and the fuelling machine enclosure is sealed olf by the wall structure of this invention.

The wall `structure is designed so that any rise in the enclosure pressure greater than 2 p.s.i.g., such as would be the result of an accident, will blow out the panels. This provides a free ow of the enclosure atmosphere to the reactor building, where it can be contained, and relieves any rapid build-up of pressure in the enclosure.

It is, however, not intended to limit the wall structure to such a use. The wall structure according to the invention may be used as a safety feature to relieve rapid buildup of pressure in any suitable enclosure.

Referring now to FIGURE 1, there is shown the supporting framework of a wall module, consisting of upright, supporting members 10 and 11 and cross supporting members 12, 13 and 14 `connected therewith, the members dening a pair of substantially rectangular areas therebetween. It should be noted that while the wall structure is described in FIGURE l in an orientation where members 1l) and 11 are upright and members 12, 13 and 14 are cross members, the members 10 and 11 could extend horizontally with the cross members 12, 13 and 14 at right angles thereto. The supporting members are preferably constructed from steel or some other suitable structural material. Members 10, 11, 12 and 13 may be I beams and member 14 is a bar of rectangular cross-section, as can be seen more clearly in FIGURE 2. A connecting passage 24 is formed in cross member 14 with an opening 30 to the front surface of the member. The passage 24 may extend longitudinally to a point where convenient connection may be made, to a vacuum system. In practice, for convenience in connecting a number of blowout panels, the passage 24 may extend longitudinally throughout member 14 and may communicate with a terminating connection at both ends. The terminating connection may, in fact, be in members 10 and 11.

Also shown in FIGURE l are blowout panels 15 and 16. Panel 15 is Situated above supporting member 14 with its horizontal upper dege behind a portion of supporting member 12. Panel 16 is situated below supporting member 14 with its horizontal lower edge behind a portion of supporting member 13. Referring to FIGURE 2, it can be seen that the right hand surfaces of panels 15 and 16 and supporting member 14 lie in the same plane. These surfaces face towards the enclosure, whose pressure is to be contained up to a predetermined value, and form a pressure retaining wall.

The blowout panels 15 and 16 are preferably formed from aluminum or other suitable material. Panels with a honeycomb core formed from aluminum foil or paper and covered with an aluminum skin have been tested and proved satisfactory. The thickness of the blowout panels 15 and 16 is governed by the requirement that they should be suciently rigid so that only a slight deformation occurs when containing the maximum pressure for which the enclosure is designed.

The gaps between the blowout panels and the supporting framework are sealed all around the edges of the panels by a sealing tape as indicated at 17 and 18 in FIG- URE 2. More generally, the sealing tape may be expressed as sealing means providing a frangible or yieldable support for the panels. Any suitable sealing tape may be used, it has been found that both aluminum foil used with an epoxy adhesive and vinyl plastic pressure sensitive tapes are suitable. Clearance should be provided at the free edges of the blowout panels to ensure that there will be no interference with their movement when the panels are blown outwards. Typically the clearance at the free edges of the blowout panel is 1/s inch and sealing tape 4 inches wide has given satisfactory sealing.

FIGURE 2 also shows a vacuum panel or locking member 19 having abutments 20 and 21. Abutment 20 is adapted to hold the lower edge of panel 15 in position as it is urged outwards by the excess pressure in the enclosure. Similarly, abutment 21 holds the upper edge of panel 16 in position. The vacuum panel 19 is of smaller area than the blowout panels 15 and 16 and may be constructed from the same materials, that is preferably an aluminum covered honeycomb core. The abutments 20 and 21, which may be replaced by separate spacing members, may be made from solid aluminum.

A sealing ring 22 is mounted on vacuum panel 19 and forms a seal between the vacuum panel and supporting member 14. A vacuum chamber 23 forming part of the holding means for the vacuum panel is thus formed between the vacuum panel 19 and the supporting member 14. Opening 30 and connecting passage 24, in supporting member 14, communicates with this Vacuum chamber and serves to connect chamber Z3 to a vacuum pump and reservoir (not shown), the whole assembly thus constituting the holding means.

A preferred form of sealing ring 22 is constructed as follows. A thin plywood rim is glued to the vacuum panel 19 at the desired position of the seal, preferably adjacent to the perimeter of the vacuum panel. A length of neoprene tubing having a diameter substantially equal to the thickness of the plywood rirn, for example, one-half inch, is formed into an endless tube and stretched over the plywood rim. A simpler form of sealing is formed by a closed ring of black solid neoprene or closed cell sponge neoprene cemented to the supporting member 14. This last form of sealing does not produce as high a degree of vacuum as the method using the plywood rim, but is acceptable in applications where a lower degree of pressure containment is required.

While a single wall module has been shown in FIG- URES 1 and 2, it will be clear that additional modules can be added above I beam 12 and below I beam 13. Similarly, additional modules can be added to the left of supporting member and to the right of supporting member 11 in FIGURE 1. In any wall formed from a number of modules the connecting passages 24 are all connected together and to the vacuum pump and reservoir.

The operation of a wall module of this invention will now be explained in conjunction with FIGURE 2. The area to the right hand side of the panels in FIGURE 2 may be considered as an enclosure liable to be subject to a sudden undesired rise in pressure andthe area to the left-hand side to be at normal atmospheric pressure.

Chamber 23 is evacuated by means of connecting pipe 24 and vacuum panel 19 is held in position against supporting member 14 by atmospheric pressure. When the enclosure (at the right hand side of FIGUFRE 2) is also at atmospheric pressure and blowout panels and 16 are held in position by sealing tapes 17 and 18 extending around their perimeters. As the pressure in the enclosure increases over atmospheric pressure the blowout panels are urged to the left. Any movement in a leftward direction of the blowout panels is restrained by the I beams 4 along one horizontal edge of each panel and the vacuum panel abutments along the other horizontal edge.

As the pressure in the enclosure increases a point will be reached when the force exerted on the vacuum panel 19 by the blowout panels 15 and 16 is suiiicient to overcome the force urging the vacuum panel against supporting member 14. The consequent movement of vacuum panel 19 and seal 22 allows air to enter vacuum chamber 23 and thus remove the force which had been urging the vacuum panel against the supporting bar 14. The vacuum panel is then pushed away from the wall framework leaving the blowout panels restrained only by the adhesive tape which cannot hold the panels against the force exerted by the excess pressure in the enclosure. The blowout panels are then blown out of position enabling a rapid relief of the excess pressure in the enclosure.

If a pressure relief wall is composed of more than one wall module, as is generally the case, all the vacuum chambers 23 are connected to a common vacuum reservoir through connecting passages 24. This has the effect that when the sealing ring of any one of the vacuum panels is displaced the vacuum is removed from the vacuum chambers of all the modules. This in turn leads to all the vacuum panels being removed simultaneously and all the blowout panels being swept out of position by the excess pressure. FIGURE 3 shows a wall structure composed of two modules of the type shown in FIGURE l. The elements of the wall modules are identical to those already described and are designated by the same reference numerals. The vacuum passages 24 of each wall module are connected in common so that the displacement of one vacuum panel removes the suction supporting the other. The common vacuum passage thus forms a pneumatic interconnecting means between the vacuum panels.

The theoretical values of pressures at which a wall module will collapse may be calculated as follows: The force applied to one of the blowout panels is the excess of the enclosure pressure over atmospheric pressure times the panel area. The force applied to the vacuum panel is atmospheric pressure times the vacuum panel area, assuming a perfect vacuum in the vacuum chamber which is a reasonable approximation to the practical condition.

The force applied to a blowout panel is shared equally between one I beam and one abutment of the vacuum panel. The force Iapplied to the applied to the vacuum panel is shared equally between the two blowout panels. Thus the balance of forces when the module is on the point of collapse is expressed by [Pe'"Pa]ABP-PaAVP where Pe is the enclosure pressure,

Ia is atmospheric pressure,

ABP is the area of a blowout panel, and AVP is the area of the vacuum panel.

This equation may be rearranged to give the value of enclosure pressure at which the collapse of the pressure relief wall should be expected:

Typical dimensions of units which have been tested are aluminum blowout panels 70x30"x1 having a weight of approximately 15 lbs., and vacuum panels 70"x8x 1" having a weight of approximately 4 lbs. This arrangement had a vacuum chamber area of cu. in. and collapsed at an enclosure excess pressure of 2 p.s.i.g. Panels of these dimensions were not damaged by collapse of the wall which is thus capable of immediate reassembly.

Thus there has been described a wall structure particularly adapted to relieve overpressure conditions in nuclear reactor buildings.

1. A building structure comprising:

a fiat framework formed by a plurality 0f rigid members defining a plurality of areas therebetween and having a first side and a second side;

a plurality of blowout panels of such configuration to pass through said defined areas each covering a major portion of one of said defined areas, and positioned on said second side of said framework;

a plurality of locking members each one associated with a pair of -blowout panels;

means supporting each of said locking members in an operative position engaging said ass-ociated pair of blowout panels restraining movement of said blowout panels from said 4second side towards said first side; and

pneumatic interconnecting means responsive t-o the -displacement of one of said locking members from its operative position to effect the removal of the remainder of said locking members from their operative positions.

2, A building structure Iforming part of a wall of a sealed pressurized enclosure comprising:

a fiat framework formed by a plurality of rigid members defining a plurality of areas therebetween, said framework having a first side and ya second side;

`a plurality of blowout panels of such configuration to pass through said areas each covering a major portion of one of said defined areas;

sealing means between said panels and said framework providing a yieldable support for said panels;

said sealing means, blowout panels and framework forming an impervious wall for said enclosure;

a vacuum panel normally held in an operative position by a predetermined suctional force against that side of the framework remote Ifrom the enclosure; and

abutments mounted on said vacuum panel engaging said blowout panels and restraining said blowout panels from movement away from said enclosure.

3. A building structure comprising:

a fiat framework formed by a plurality of-rigid members defining a plurality of substantially rectangular areas therebetween and having a first side and a second side;

a plurality of substantially rectangular blowout panels of such configurations to pass through said defined areas each covering a major portion of one of said defined areas;

one edge of each blowout panel engaging a portion of said framework on said second side to restrain said panels from movement towards said first side and the opposite edge of each blowout panel being spaced slightly `from said framework;

sealing means between said panels and said framework providing a yieldable support for said panels;

a vacuum panel;

a sealing ring positioned adjacent the periphery of said vacuum panel;

said vacuum panel and sealing ring being normally positioned at said first side of said framework adjacent to one of said rigid members forming a vacuum chamber enclosed by said one rigid member, said vacuum panel and said sealing ring;

means for evacuating said vacuum chamber; and

abutments mounted between said vacuum panel and said blowout panels restraining said blowout panels from movement towards said first side.

4. A building structure comprising:

a framework having at least a pair of parallel spaced apart supporting members extending in a first direction and at least a pair of parallel spaced apart supporting members connected therewith extending in a second direction at right angles to said first direction;

a substantially rectangular blowout panel having first and second -opposed edges with a first length therebetween and third and fourth opposed edges with 4a second length therebetween;

said framework receiving said panel with said first length extending in said second direction;

said first length being slightly less than the spacing between said supporting members extending in said first direction permitting said panel to fit therebetween;

said second length being slightly greater than the spacing between said supporting members extending in said second direction;

said third edge directly engaging a portion of one of said members extending in said second direction to restrain said panel from movement in a predetermined direction and said fourth edge being spaced slightly from an adjacent one of said members extending in said second direction;

sealing means Ibetween said panel and said framework providing a frangible support for said panel;

a locking member releasably secured to said adjacent one of said members and having a projecting lip engaging said fourth edge to restrain the panel at said fourth edge from movement in said predetermined direction;

said locking member releasing from said adjacent one of said members when a predetermined pressure is applied thereto by said fourth edge of said panel.

5. A building structure comprising:

a supporting framework including la first, second and third parallel spaced apart supporting members extending in a first direction and fourth and fifth parallel spaced apart supporting members connected therewith extending in a second direction at right angles to said first direction;

a first blowout panel of substantially rectangular shape having one edge engaging said first member restraining said one edge from movement in one direction and having it-s opposite edge spaced slightly from said second member;

a second blowout panel of substantially rectangular shape having one edge engaging said third member restraining said one edge of said second panel from movement in said one direction and having its opposite edge spaced slightly from said second member;

the distance between the two remaining edges of said first panel and the distance between the two remaining edges of s-aid second panel being slightly less than the distance between said fourth and fifth supporting members;

sealing means between said panels and said framework providing a yieldable support for said panels;

a vacuum panel with a sealing ring positioned adjacent the periphery of said vacuum panel;

said vacuum panel being normally positioned adjacent to said secon-d member forming a vacuum chamber contained by said vacuum panel, said sealing ring and said second member;

a connectingpassage in said second member lea-ding to said vacuum chamber; and

a'butments mounted on said vacuum panel engaging said opposite edges of said first and second blowout panels and restraining said opposite edges from movement in said one direction.

6. A building structure comprising:

a supporting framework including a first, second, and third parallel spaced apart supporting members extending in a first direction and fourth and fifth parallel spaced apart supporting members connected therewith extending in :a second direction at right angles to said first direction;

a first blowout panel of substantially rectangular shape having one edge engaging said first member restraining said one edge from movement in one direction and having its opposite edge spaced slightly from said secon-d member;

a second blowout panel of substantially rectangular shape having one edge engaging said third member restraining said one edge of said second panel from movement in said one direction and having its opposite edge spaced slightly from said second member;

the distance between the two remaining edges of said first panel and the distance between the two `remaining edges of said second panel being slightly less than the distance between said fourth and fifth supporting members;

sealing means between said panels and said framework providing a yieldable support for said panels;

a vacuum panel with a sealing ring positioned adjacent ythe periphery of said vacuum panel;

said vacuum panel Ibeing normally positioned adjacent to said second member forming a vacuum chamber contained by said vacuum panel, said sealing ring and said second member;

a connecting passage in said second member leading to said vacuum chamber;

a first spacing member interjacent one edge of said vacuum panel and said opposite edge of said first blowout panel;

a second spacing member interjacent the opposite edge of said vacuum panel and said opposite edge of said second blowout panel; and

said first and second spacing members restraining said opposite edges of said blowout panels from movement in said one direction.

7. A building structure comprising:

a supporting framework including first, second and third parallel spaced apart supporting members extending ina horizontal direction and fourth and fifth parallel spaced .apart supporting members connected therewith and extending in a Vertical direction;

a first blowout panel of substantially rectangular shape arranged vertically with its upper edge engaging said first member restraining said upper edge from sideways movement in one direction and with its lower edge above and adjacent to said second member;

a second blowout panel of substantially rectangular shape arranged vertically with its lower edge engaging said third member restraining said lower edge of said second panel from sideways movement in said one direction and with its upper edge below and adjacent to said second member;

the distance between the vertically extending edges of each said blowout panel being slightly less than the distances between said fourth and fifth members;

sealing means between said panels and said Vframework providing a yieldable support for said panels;

`a vacuum panel wtih a sealing ring positioned adjacent the periphery of said vacuum panel;

said vacuum panel being normally positioned adjacent to said second member forming a vacuum chamber contained by said vacuum panel, said sealing ring and said second member;

a connecting passage in said second member leading to said vacuum chamber; and

abutments mounted on said vacuum panel engaging said lower edge of said first blowout panel and said upper edge of said second blowout panel and restraining said lower edge of `said first blowout panel and said upper edge of said second blowout panel from sideways movement in said one direction.

8. A building structure comprising:

a supporting framework including first, second and third parallel spaced apart supporting members extending in a first direction and fourth and fifth parallel spaced apart supporting members connected therewith extending in a second direction at right angles to said first direction;

a first blowout panel of substantially rectangular shape having one edge engaging said first member restraining said one edge from movement in one direction and having its opposite edge spaced from said second member at a distance in the range of onesixteenth to one-half inch;

la second blowout panel of substantially rectangular shape having one edge engaging said third member restraining said one edge of said second panel from movement in said one direction and having its opposite edge spaced from said second member at a distance in the range of one-sixteenth to one-half inch;

a further edge of said first blowout panel and a further edge of said second blowout panel being spaced from said fourth member at a distance in the range of onesixteenth to one-half inch;

the remaining edge of said first blowout panel and the remaining edge of said second blowout panel being spaced from said fth member at a distance in the range of one-sixteenth to one-half inch;

sealing meanst between said edges of said blowout panels and said framework providing a yieldable support for said blowout panels;

a substantially rectangular, vacuum panel with a continuous sealing ring positioned on one face adjacent the periphery of said vacuum panel;

said vacuum panel being normally positioned adjacent to said second member forming a vacuum chamber contained by said one face of said vacuum panel, said sealing ring and said second member;

a connecting passage in said second member leading to said vacuum chamber; and

abutments mounted on said vacuum panel engaging said opposite edges of said first and second blowout panels and restraining said opposite edges from movement in said one direction.

References Cited UNITED STATES PATENTS 1,369,566 2/1921 Smidley 98-95 2,358,143 9/1944 Castor 52-100 2,820,475 l/l958 Hobbs 98-95 3,258,890 7/1966 Dirkse 52-309 FRANK L. ABBOTT, Primary Examiner.

R. S. VERMUT, Assistant Examiner. 

1. A BUILDING STRUCTURE COMPRISING: A FLAT FRAMEWORK FORMED BY A PLURALITY OF RIGID MEMBERS DEFINING A PLURALITY OF AREAS THEREBETWEEN AND HAVING A FIRST SIDE AND A SECOND SIDE; A PLURALITY OF BLOWOUT PANELS OF SUCH CONFIGURATION TO PASS THROUGH SAID DEFINED AREAS EACH COVERING A MAJOR PORTION ONE OF SAID DEFINED AREAS, AND POSITIONED ON SAID SECOND SIDE OF SAID FRAMEWORK; A PLURALITY OF LOCKING MEMBERS EACH ONE ASSOCIATED WITH A PAIR OF BLOWOUT PANELS; MEANS SUPPORTING EACH OF SAID LOCKING MEMBERS IN AN OPERATIVE POSITION ENGAGING SAID ASSOCIATED PAIR OF BLOWOUT PANELS RESTRAINING MOVEMENT OF SAID BLOWOUT PANELS FROM SAID SECOND SIDE TOWARDS SAID FIRST SIDE; AND PNEUMATIC INTERCONNECTING MEANS RESPONSIVE TO THE DISPLACEMENT OF ONE OF SAID LOCKING MEMBERS FROM ITS OPERATIVE POSITION TO EFFECT THE REMOVAL OF THE REMAINDER OF SAID LOCKING MEMBERS FROM THEIR OPERATIVE POSITIONS. 